Admittedly I haven't had too many dipping sauces, since sweet and sour is my absolute favorite and I see no reason to branch out. Usually if a place doesn't have it then I'll go with BBQ sauce instead.
I'm not a fan of dipping sauces because most of them have vinegar and I have an extreme aversion to vinegar. I don't like any dressings or condiments for the same reason.
I really like mumbo sauce, but the really good ones I’ve had are only found in the dmv. Open Pitt bbq is a good substitute when I’m craving it but aren’t close enough to get any. I’m also a fan of Chick-fil-A sauce and their sweet sriracha and polynesian. Honey mustard is good too but I’m very picky about it, there are only certain ones I like.